Blame view

ffmpeg-4.2.2/libavresample/resample_template.c 3.69 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
  /*
   * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include <math.h>
  #include <stdint.h>
  
  #include "libavutil/common.h"
  #include "internal.h"
  
  #if defined(CONFIG_RESAMPLE_DBL)
  #define SET_TYPE(func)  func ## _dbl
  #define FELEM         double
  #define FELEM2        double
  #define FELEML        double
  #define OUT(d, v) d = v
  #define DBL_TO_FELEM(d, v) d = v
  #elif defined(CONFIG_RESAMPLE_FLT)
  #define SET_TYPE(func)  func ## _flt
  #define FELEM         float
  #define FELEM2        float
  #define FELEML        float
  #define OUT(d, v) d = v
  #define DBL_TO_FELEM(d, v) d = v
  #elif defined(CONFIG_RESAMPLE_S32)
  #define SET_TYPE(func)  func ## _s32
  #define FELEM         int32_t
  #define FELEM2        int64_t
  #define FELEML        int64_t
  #define OUT(d, v) d = av_clipl_int32((v + (1 << 29)) >> 30)
  #define DBL_TO_FELEM(d, v) d = av_clipl_int32(llrint(v * (1 << 30)));
  #else
  #define SET_TYPE(func)  func ## _s16
  #define FELEM         int16_t
  #define FELEM2        int32_t
  #define FELEML        int64_t
  #define OUT(d, v) d = av_clip_int16((v + (1 << 14)) >> 15)
  #define DBL_TO_FELEM(d, v) d = av_clip_int16(lrint(v * (1 << 15)))
  #endif
  
  static void SET_TYPE(resample_nearest)(void *dst0, int dst_index, const void *src0, unsigned int index)
  {
      FELEM *dst = dst0;
      const FELEM *src = src0;
      dst[dst_index] = src[index];
  }
  
  static void SET_TYPE(resample_linear)(ResampleContext *c, void *dst0, int dst_index,
                                        const void *src0, unsigned int index, int frac)
  {
      FELEM *dst = dst0;
      const FELEM *src = src0;
      int i;
      unsigned int sample_index = index >> c->phase_shift;
      FELEM2 val = 0;
      FELEM *filter = ((FELEM *)c->filter_bank) +
                      c->filter_length * (index & c->phase_mask);
      FELEM2 v2 = 0;
  
      for (i = 0; i < c->filter_length; i++) {
          val += src[sample_index + i] * (FELEM2)filter[i];
          v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
      }
      val += (v2 - val) * (FELEML)frac / c->src_incr;
  
      OUT(dst[dst_index], val);
  }
  
  static void SET_TYPE(resample_one)(ResampleContext *c,
                                     void *dst0, int dst_index, const void *src0,
                                     unsigned int index, int frac)
  {
      FELEM *dst = dst0;
      const FELEM *src = src0;
      int i;
      unsigned int sample_index = index >> c->phase_shift;
      FELEM2 val = 0;
      FELEM *filter = ((FELEM *)c->filter_bank) +
                      c->filter_length * (index & c->phase_mask);
  
      for (i = 0; i < c->filter_length; i++)
          val += src[sample_index + i] * (FELEM2)filter[i];
  
      OUT(dst[dst_index], val);
  }
  
  static void SET_TYPE(set_filter)(void *filter0, double *tab, int phase,
                                   int tap_count)
  {
      int i;
      FELEM *filter = ((FELEM *)filter0) + phase * tap_count;
      for (i = 0; i < tap_count; i++) {
          DBL_TO_FELEM(filter[i], tab[i]);
      }
  }
  
  #undef SET_TYPE
  #undef FELEM
  #undef FELEM2
  #undef FELEML
  #undef OUT
  #undef DBL_TO_FELEM